The invention relates to a rotary hammer and, more particularly, relates to a switch for switching between three modes of the hammer, namely, drilling, hammer drilling and chiselling.
Known rotary hammers of this type (German Patent Application P 40 13 512) with switching between more than two operating modes by means of a single switching element are known. In these, there is a parallel arrangement of the axis of the hammer spindle, of the armature shaft of the electric motor and of the intermediate shaft which is driven by armature shaft. In the activated case, the intermediate shaft drives the hammer mechanism and brings about the rotation of the tool holder. All the coupling and uncoupling processes for the activation and deactivation of the rotary drive and of the hammer mechanism therefore take place in one direction, namely parallel to the axis of the hammer spindle, so that the operating mode in question can be set by successive actuation of different coupling arrangements.
In the case of larger rotary hammers in which the drive motor is arranged with its armature shaft at a right angle to the axis of the hammer spindle, it is not at present possible to carry out switching between more than two operating modes, i.e., in addition to switching between activated and deactivated rotary drive or to switching between activated and deactivated hammer mechanism, with a single switching element. Rather, separate switching elements are used. One moves the coupling arrangement for the rotary drive in a direction parallel to the axis of the hammer spindle. This parallel movement generally is directed coaxially relative to the axis of the hammer spindle. The other switching element displaces the coupling arrangement for the activation and deactivation of the hammer mechanism parallel or coaxially relative to the armature shaft.